Transition metal and transition metal oxide glove and condom formers and coatings therefor

ABSTRACT

A glove or condom former made of or coated with one or more transition metals and/or transition metal oxides is provided that exhibits improved durability over glove and condom formers currently in use.

FIELD OF THE INVENTION

The invention relates to glove and condom formers that are used in themanufacture of natural latex or synthetic polymer gloves and condoms.This invention further relates to glove or condom formers and coatingsfor glove and condom formers made of one or more transition metalsand/or transition metal oxides.

BACKGROUND OF THE INVENTION

Glove and condom formers are rigid molds sized and shaped to define thedimensions of the finished products. These formers are used to makegloves such as latex examination gloves and surgical gloves or condoms.The formers are typically made of ceramic, porcelain, plastic, steel oraluminum, and are dipped, usually fingers first in the case of a gloveformer into a liquid latex bath, including admixed chemicals, where thelatex adheres to the former. The glove or condom formers may be heatedprior to beginning the dipping process. The latex is dried and the gloveor condom is released from the former usually by peeling the glove orcondom from the glove or condom from the former and inverting thearticle in the process. The articles may be removed from the former inwater.

After repeated cycles of chemical dips such formers begin to degrade andmust be replaced. Glove and condom formers are usually pre-coated with acoagulant to gel the latex and to facilitate removal of the article fromthe former. Typical coagulants include calcium nitrate. Additional dipsin latex baths that contain fillers may also be required. As a benchmarkfor durability, porcelain formers remain in good condition for up to twoweeks when exposed to a concentrated solution of potassium hydroxide.The gloves or condoms may also go through leaching and washing cycles toremove residual chemicals before being stripped from the former. Thefinished articles are then removed from the former such that the outerlayer from the former will be the innermost layer of the glove orcondom. The articles may then be sterilized and packaged for shipping.

There is a need for glove and condom formers of a durable material thatwill reduce the frequency with which the formers must be replaced. It isdesirable that the durable formers do not otherwise interfere with thequality of the glove or condom produced.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a glove or condomformer or a coating for a glove of condom former comprising one or moretransition metals and/or transition metal oxides.

Another object of the present invention is to provide a method forproducing gloves or condoms using a glove or condom former comprisingone or more transition metals and/or transition metal oxides or coatedwith one or more transition metal and/or transition metal oxides.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides glove and condom formers with enhanceddurability as compared to ceramic, porcelain, plastic, steel or aluminumglove and condom formers currently in use.

In one embodiment of the present invention, the glove and condom formerscomprise one or more transition metals and/or transition metal oxides.Examples of transition metals and transition metal oxides useful in theformers of the present invention include, but are not limited to,titanium, titanium oxides, titanium alloys, zirconium, zirconium alloys,zirconium oxide, niobium, niobium alloys, niobium oxides, tantalum,tantalum alloys, tantalum oxides, hafnium, hafnium alloys, hafniumoxides, chromium, chromium alloys, chromium oxides, molybdenum,molybdenum alloys and molybdenum oxides. Preferably, in this embodiment,the glove or condom former consists essentially of one or more of thesetransition metals and/or one or more transition metal oxides. Morepreferred is a glove or condom former comprising titanium, titaniumoxide, zirconium and/or zirconium oxide.

Formers consisting essentially of transition metals and/or transitionmetal oxides can be produced by any commercially available powderforming technique such as, but not limited to, slip casting, gelcasting, injection molding, solid free forming, or rapid prototyping,followed by sintering. For example, slip casting and sintering of one ormore transition metals and/or transition metal oxides into a glove orcondom former is conducted, by dispersing the transition metal or metalsand/or transition metal oxide or oxides in a solvent such as water alongwith a binder and viscosity modifying agent. The dispersion preferablyranges from about 25% to 85% solids. The binder and viscosity modifierare preferably cellulose-based materials. However, other organic orinorganic binders can also be used. The resulting dispersion or slurryis referred to as the slip. The slip is poured into a commerciallyavailable mold, preferably a plaster of paris mold, and allowed to setfor up to five hours before the excess slip is drained. The former isremoved from the mold and allowed to air dry. After drying, the formeris heated in an oven at temperatures of 1000 C to 1500 C. This firing orheating is the sintering step.

In another embodiment of the present invention, coatings comprising oneor more transition metals and/or transition metal oxides are providedfor standard glove or condom formers or transition metal and/ortransition metal oxide formers of the present invention. For purposes ofthe present invention, by “standard glove or condom former” it is meanta former comprising a known material for formers including, but notlimited to, ceramic, porcelain, plastic, steel or aluminum. Examples oftransition metals and/or transition metal oxides useful as coatings forthis embodiment include, but are not limited to, titanium, titaniumoxides, titanium alloys, zirconium, zirconium alloys, zirconium oxide,niobium, niobium alloys, niobium oxides, tantalum, tantalum alloys,tantalum oxides, hafnium, hafnium alloys, hafnium oxides, chromium,chromium alloys, chromium oxides, molybdenum, molybdenum alloys andmolybdenum oxides. Preferably, in this embodiment, the coating consistsessentially of one or more transition metals and/or transition metaloxides. Preferred transition metals and transition metal oxides forcoating the former include titanium, titanium oxide, zirconium andzirconium oxide.

For application of the coating, it is preferred that one or moretransition metals and/or transition metal oxides be mixed with a solventsuch as water. A binding agent can also be added. For standard glove orcondom formers, it is preferred that the transition metal coating beapplied via thermal spraying in accordance with well known techniquessuch as plasma spraying or HVOF (high velocity oxyfuel). For transitionmetal or transition metal oxide formers, the coating is preferablyapplied following the powder formation technique, but prior tosintering. For example, if the transition metal and/or transition metaloxide former is formed by slip casting, the coating, prepared by mixingone or more transition metals and/or transition metal oxides with asolvent such as water, is preferably applied to the former by paintingor atomizing prior to the sintering cycle.

Accelerated chemical resistance testing has been conducted to test thedurability of titanium oxide (TiO₂) as a material for a solid former.One accelerated aging test was performed by immersing the titanium oxidesample in a 20% solution of potassium hydroxide at 170° F. The titaniumoxide sample was removed on a periodic basis and evaluated. It was notedthat after six (6) weeks of immersion, the sample did not show anymeasurable weight change or visible surface defects. In comparison,standard porcelain formers degrade after two weeks of exposure topotassium hydroxide as evidenced by pitting in the former and byproducing gloves that have pinhole sized defects in the gloves. Fromthese experiments, it is expected that transition metal and/ortransition metal oxide oxides formers or formers coated with transitionmetals and/or transition metal oxides will exhibit improved durabilityon the order of 300%.

It should be understood that various changes and modifications to theembodiments described herein would be apparent to those skilled in theart. Such changes and modifications can be made without departing fromthe spirit and scope of the present invention and without demising theattendant advantages. It is, therefore, intended that such changes andmodifications be covered by the appended claims.

1. A glove or condom former comprising one or more transition metals ortransition metal oxides.
 2. The glove or condom former of claim 1consisting essentially of one or more transition metals or transitionmetal oxides.
 3. The glove or condom former of claim 1 wherein thetransition metal or transition metal oxide is selected from the groupconsisting of titanium, titanium oxides, titanium alloys, zirconium,zirconium alloy, zirconium oxide, niobium, niobium alloys, niobiumoxides, tantalum, tantalum alloys, tantalum oxides, hafnium, hafniumalloys, hafnium oxides, chromium, chromium alloys, chromium oxides,molybdenum, molybdenum alloys and molybdenum oxides.
 4. The glove orcondom former of claim 1 wherein the transition metal or transitionmetal oxide is titanium, titanium oxides, zirconium, or zirconiumoxides.
 5. The glove or condom former of claim 1 further comprising oneor more transition metals or transition metal oxides coating on theformer.
 6. A glove or condom former comprising a standard glove orcondom former coated with a one or more transition metals or transitionmetal oxides.
 7. The glove or condom former of claim 6 wherein thetransition metal is selected from the group consisting of titanium,titanium oxides, titanium alloys, zirconium, zirconium alloy, zirconiumoxide, niobium, niobium alloys/niobium oxides, tantalum, tantalumalloys, tantalum oxides, hafnium, hafnium alloys, hafnium oxides,chromium, chromium alloys, chromium oxides, molybdenum, molybdenumalloys and molybdenum oxides.
 8. The glove or condom former of claim 6wherein the standard former is coated with titanium, titanium oxides,zirconium, or zirconium oxide.